Production of formic acid



Patented Jan. 6, 1925.

D UNITED s'ra'rs ,szaas I osric.

KURT HEINRICH MEYER, 0F MANNHEIMQ AND J'OHANNES MI'iLLER, or EPrs'rEIN,

NEAR FRANKENTHAL, GERMANY, AssIeNoRs TO BADISCHE ANILIN- & SODA- ;FABRIK; or LUDwIGsHAEEN-oN-THE-RHINE, GERMANY, A CORPORATION on GER- MANY.

PRODUCTION or EoRMIo ACID.

Nb Drawing.

To all whom it may concdm:

Be it known that we, KURT HEINRICH MEYER and JoHANN s Mr'iLLER, citizens of the German Empire, residing at Mannheim and Eppstein, near Frankenthal, respectively, Germany, have invented new and useful Improvements in the Production of 'Formic Acid, of which the following is a specification. 4 This in vention relates to the production of formic acidfrom ammonium. formate. As is known, in the decomposition of formates by sulfuric acid heat is generated which must be checked in order to avoid dccomposition of theformic acid.

lVe have found that formic acid can be produced in an excellent manner from ammonium formate by decomposing with sulfuric acid, by causing the latter to act on the ammonium formate in the presence of form amide. The formamide acts as a diluent enabling the acid to-distribute, uniformly in the reaction mixture thus avoiding local superheating and decomposition. The formamide can also simultaneously be converted into formic acid and ammonium sulfate,

I .for which reaction the presence of one mo- I produceisuch mixtures, ammonium formate may be heated to say, between 200 and 230 degrees Centigrade, until the desired degree of dehydration is obtained. Or the mixture may be directly produced by causing carbon monoxid to react with ammonia and water under pressure; by finally removing the water a mixture -of ammonium formate and formamide with more or less free formic.

acid is obtained.

The invention is more Application filed August 17, 1923. Serial No. 657,951.

the following examples to which however the invention is not limited. The parts are by weight.

Example 1.

-.,to more than 90 per cent of the theoretical quantity of formic acid.

Example 6.58 parts of ammonium formate, .100 parts of formamide and 14 parts of water are stirred to form a paste and 646.5 parts of sulfuric acid of 96 per cent are then slowly run in, while stirring and cooling, if required. The temperature is then raised and the formic acid distilled oil. The yield surpasses 90 per cent of the theoretically caleulated yield.

We claim:

l. The. process of manufacturing formic acid which consists in decomposing a mixture of ammonium formate and forma-mide with sulfuric acid.

2. The process of manufacturing formic acid which consists in -decomposing a mixture of ammonium formate and formamidc with sulfuric acid in the. presence of water.

The process of manufacturing formic acid which consists in decomposing a mixture of ammonium formate and formamide with sulfuric acid in the presence of at least one molecularproportion of water to each .one molecular proportion of formamide.

' 4;. The processof manufacturing formic acid which consists in heating ammonium formate to convert it into a mixture of ammonium formats and formamide and decomposing the mixture with sulfuric acid in the presence of at least one molecular pro- Ice portion of formamide.

4T Q process Lot/manufact ing fe fm portion of water to each one molecular proacid which consists in causing carbon monto each one molecular proportion of formoxid to react with ammonia in the presence of amide.- water and under pressure, evaporating the In testimony whereofwe have hereunto solution and decomposing'the remaining mixset our hands. fl ture with sulfuric acid and in thepresence KURT HEINRICH MEYER. "of at least one molecular proportion of Water J OHANN ES MULLER. 

